Serendipitous discovery of a novel protostrongylid (Nematoda: Metastrongyloidea) in caribou (Rangifer tarandus), muskoxen (Ovibos moschatus) and moose (Alces alces) from North America by DNA sequence comparisons.

Authors: KUTZ, SUSAN - University Of Calgary; Asmundsson, Ingrid; Hoberg, Eric; APPLEYARD, GREG - University Of Calgary; JENKINS, EMILY - University Of Saskatoon; BECKMEN, KIMBERLEE - Alaska Department Of Fish And Game; BRANIGAN, MARSHA - Government Of The Northwest Territories; BUTLER, LEM - Alaska Department Of Fish And Game; CHILTON, NEIL - University Of Saskatchewan; COOLEY, DOROTHY - Yukon Delta National Wildlife; ELKIN, BRETT - Government Of The Northwest Territories; HUBY-CHILTON, FLORENCE - University Of Saskatchewan; JOHNSON, DEBORAH - Government Of The Northwest Territories; KUCHBOEV, ABDURAKHIM - Uzbekistan Academy Of Sciences; NAGY, JOHN - Government Of The Northwest Territories; OAKLEY, MICHELLE - Yukon Delta National Wildlife; POLLEY, L - University Of Saskatchewan; POPKO, RICHARD - Government Of The Northwest Territories; SCHEER, AEDES - University Of British Columbia; VEITCH, ALASDAIR - Government Of The Northwest Territories

Submitted to: Canadian Journal of Zoology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2007
Publication Date: 4/1/2007
Citation: Appleyard, G.D., Kutz, S.J., Asmundsson, I.M., Hoberg, E.P., Jenkins, E.J., Lankester, M., Beckmen, K., Branigan, M., Huby-Chilton, F., Cooley, D., Elkin, B., Johnson, D., Kuchboev, A., Nagy, J., Oakley, M., Olsen, B., Popko, R., Scheer, A., Veitch, A. 2007. Serendipitous discovery of a novel protostrongylid (Nematoda: Metastrongyloidea) in caribou (Rangifer tarandus), muskoxen (Ovibos moschatus) and moose (Alces alces) from North America by DNA sequence comparisons. Canadian Journal of Zoology. 85:1143-1156.

Interpretive Summary: Clear definitions for biodiversity of parasites and pathogens are primary information needed to understand geographic and host associations, and to identify how ecological perturbation may influence patterns of disease. In a broad-based collaboration of parasitologists and wildlife biologists in the United States, and Canada we report the discovery of a previously unknown lungworm (protostrongylid) parasite with an apparently widespread geographic distribution in northern North America. Many protostrongylid nematode species produce first-stage larvae with dorsal tail spines (DSL) that are shed in feces of ungulates. Definitive identification of DSL is rarely possible through comparative morphology; however, fecal samples are often the only feasible means to assess the distribution of these nematode parasites in wildlife. Molecular techniques have now been employed in geographically extensive surveys to differentiate among protostrongylid species using DNA from individual larvae. Sequence data were used to differentiate DSL recovered from feces of caribou (Rangifer tarandus tarandus, R. t. caribou, R. t. grantii), muskoxen (Ovibos moschatus moschatus and O. m. wardi), and moose (Alces alces gigas) in the North American Arctic and Subarctic extending from Alaska to Labrador. A previously uncharacterized and genetically distinct species was recognized based on 29 DSL from 18 ungulate hosts. These sequences indicate a discrete lineage of a currently unknown protostrongylid, infecting muskoxen, caribou and moose across northern North America. Results of our research highlight the continuing need to conduct survey and inventory for biodiversity as a foundation for understanding the distributions for parasites and pathogens among ungulates that serve as food resources in northern communities.

Technical Abstract: Many protostrongylid nematode species produce first-stage larvae with dorsal tail spines (DSL) that are shed in feces of wild ungulates. Definitive identification of DSL is rarely possible through comparative morphology; however, fecal samples are often the only feasible means to assess the distribution of these nematode parasites in wildlife. Molecular techniques have now been employed in geographically extensive surveys to differentiate among protostrongylid species using DNA from individual larvae. Partial sequences from the internal transcribed spacer region of ribosomal DNA (ITS-2) were used to differentiate DSL recovered from feces of caribou (Rangifer tarandus tarandus, R. t. caribou, R. t. grantii), muskoxen (Ovibos moschatus moschatus and O. m. wardi), and moose (Alces alces gigas) in the North American Arctic and Subarctic. A previously uncharacterized and genetically distinct species was recognized based on 29 DSL from 18 ungulate hosts and 1 third stage larva from a slug (Deroceras laeve) collected in the Mackenzie Mountains, Northwest Territories. Sequence similarity among individuals of this putative species was 91-100%; additionally, at least two distinct, but similar copies of ITS-2 were identified within individual DSL. ITS-2 sequences from this putative species were 72-77% similar to that in Varestrongylus alpenae, 58-61% similar to those of elaphostrongylines (Elaphostrongylus spp. and Parelaphostrongylus spp.), and 51-60% similar to other protostrongylids known in North American and some Eurasian ungulates. These sequences indicate a discrete lineage of a currently unknown protostrongylid, infecting muskoxen, caribou and moose across northern North America. Sympatric but not concurrent infections with P. andersoni were demonstrated in caribou from localities in the Canadian Arctic and Alaska.